Medical device employing liquid crystal block copolymers and method of making the same

Abstract

A medical device, at least a portion of which is formed from a polymer composition including at least one liquid crystal block copolymer having at least one A block and at least one B block wherein the A block is formed of mesogenic repeat units and the B block is a soft block.

1. An expandable medical balloon, the medical balloon formed from a polymer composition, the polymer composition comprising about 50% to about 95% of at least one first polymer and about 5% to about 50% of at least one liquid crystal block copolymer having at least one A block and at least one B block and wherein the A block comprises mesogenic repeat units and has a polymer backbone comprising no aliphatic unsaturation; and the B block is a soft block. 
     
     
       2. The expandable medical balloon of  claim 1 , said polymer composition comprising about 70% to about 95% of said at least one first polymer and about 5% to about 30% of said at least one liquid crystal block copolymer. 
     
     
       3. The expandable medical balloon of  claim 1 , said at least one first polymer is a member selected from the group consisting of polyolefins, polyesters, polyethers, polyamides, polyimides, block copolymers comprising at least one polyolefin, polyester, polyether, polyamide, and/or polyimide segment, silicones, and mixtures thereof. 
     
     
       4. The expandable medical balloon of  claim 1 , said at least one first polymer is a thermoplastic elastomer. 
     
     
       5. The expandable medical balloon of  claim 1 , said at least one first polymer is a poly(ether-block-amide). 
     
     
       6. The expandable medical balloon of  claim 1  wherein the B block of said liquid crystal polymer is aliphatic. 
     
     
       7. The expandable medical balloon of  claim 1  wherein said B block is derived from a repeating unit selected from the group consisting of olefins, esters, ethers, amides and siloxanes. 
     
     
       8. The expandable medical balloon of  claim 5 , said at least one poly(ether-block-amide) has an (AB) n  block copolymer structure wherein n is 3 to 20 and the A block is nylon and the B block is polytetramethylene oxide. 
     
     
       9. The expandable medical balloon of  claim 8  wherein said B block of said liquid crystal block copolymer comprises amide repeat units or a polytetramethylene oxide structure. 
     
     
       10. The expandable medical balloon of  claim 9  wherein said B block is about 50% or less by weight of said liquid crystal block copolymer. 
     
     
       11. The expandable medical balloon of  claim 9  wherein said B block is about 30% or less by weight of said liquid crystal block copolymer. 
     
     
       12. The expandable medical balloon of  claim 9  wherein said B block is about 10% or less by weight of said liquid crystal block copolymer. 
     
     
       13. The expandable medical balloon of  claim 1  wherein said A block of said liquid crystal polymer comprises at least one aromatic group per repeat unit of said A block. 
     
     
       14. The expandable medical balloon of  claim 1  wherein said A block of said liquid crystal polymer comprises at least two aromatic groups per repeat unit of said A block. 
     
     
       15. The expandable medical balloon of  claim 1  wherein said B block of said liquid crystal polymer is derived from hydrophilic monomer units. 
     
     
       16. The expandable medical balloon of  claim 15  wherein said B block of said liquid crystal polymer is derived from at least one hydrophilic monomer unit which is a member selected from the group consisting of short chain aliphatic ethers, diols, dicarboxylic acids containing a metal sulfonate group, and acrylamides. 
     
     
       17. The expandable medical balloon of  claim 16  wherein said at least one hydrophilic monomer unit is a member selected from the group consisting of polyethylene oxide glycol, polytetramethylene oxide glycol, N,N-dimethylacrylamide and N-vinylpyrrolidone. 
     
     
       18. The expandable medical balloon of  claim 15  wherein said B block of said liquid crystal polymer is derived from at least one member selected from the group consisting of polyalkylene glycol copolymerized with an aliphatic dicarboxylic acid or polyalkylene glycol copolymerized a hydrophilic acrylate. 
     
     
       19. The expandable medical balloon of  claim 1  wherein said liquid crystal block copolymer further comprises a C block, the C block is derived from different mesogenic repeat units than those of the A block.